Hydrogen Engine Reaches Diesel Efficiency

The BMW Group and researchers in Austria have succeeded in developing a hydrogen combustion
engine with a diesel-like design and high-pressure direct injection technology. The newly
developed combustion system combines the strengths of spark-ignition and diesel concepts,
while utilizing the combustion properties of hydrogen. The result is an efficiency level of
up to 42 percent, on par with the best turbodiesel engines. BMW engineers developed a new
cylinder head for hydrogen operation based on a production diesel engine. The combustion
chamber of the engine was configured using numerical flow simulation. Special high-pressure
injectors directly inject hydrogen into the combustion chambers with pressures of up to
nearly 4,500 psi. Extensive test runs have shown that a combination of spark-ignition and
diesel combustion systems using surface ignition followed by a diffusion type of combustion
is the ideal solution for efficiency, power and fuel economy. Further increases in
efficiency will be possible in the future by recovering waste heat. “In light of the
limited availability of fossil fuels and the rising environmental impact from harmful
emissions, we are convinced that the H2 combustion engine will assume an important position
in the product portfolio of future alternative drive concepts.” said Professor Dr. Raymond
Freymann, for BMW.